Suction device for chimneys



Aug. 17, 1937. H. MEUTH 2,090,392

SUCTION DEVICE FOR CHIMNEYS Filed Jan. 24, 1955 Patented Aug. 17, 1937 UNl'l'E STATES Application 4 Claims.

The invention concerns a head-piece for heating and ventilating chimneys consisting of a body with vertical slits arranged especially at the places of the highest vacuum.

When the wind impinges on prismatic or round bodies, a pressure and a vacuum space are produced. According to test results, the pressure space extends in the case of round bodies over /6th of the circumference, the remaining ;ths act as a suction area.

Fig. 1 is the upright projection of the cylindrical head piece with a fixed covering screensurface with a diagram of vacuum space at the cover.

Fig. 2 is the top view of the head piece of Fig. 1 with a diagram showing the distribution of the pressure and vacuum spaces.

Fig. 3 is the upright projection of a conical head piece with movable covering screen surface I, steered by the wind by means of the vane 8.

Fig. 4 is the top view of the conical head piece of Fig. 3.

Fig. 5 is the upright projection of a conical head piece tapering downwardly with apertures and bars of equal width round the whole circumference.

Fig. 6 is a cross section r-x of Fig. 5.

In Fig. 1 and Fig. 2 are shown size and extent of pressure area i and of vacuum area 2. The places of the highest vacuum are on both sides of the narrow pressure space i, quite close to it by 3 (Fig. 2) and on the border of the cover 6 by 3 (Fig. 1).

If gases or vapours are to be drawn from hollow bodies by the suction effect of the wind flowing past them, it will be advisable to cover the outlet openings l in the surface of the body only in the narrow area of the pressure by means of a correspondingly small imperforate surface 1 (Figs. 1 and 2) and to keep open the other apertures 4 for the outlet in the whole vacuum space 2 (Fig. 2), especially on the places of the highest vacuum 3 (Fig. 2) and 3 (Fig. l, openings 1 on the border of the cover 6). For same suction effect by other directions of the wind a movable surface l (Figs. 3 and 4) steered by the wind may be arranged. For this purpose the surface I (Figs. 3 and i) is revoluble on a central pivot and counterbalanced by the vane 8. Tests have shown 50 that a particularly strong suction efiect is produced in this manner and that this suction effect is only a little smaller if the covering surface I (Figs. 1 and 2) is not imperforated but perforated,

as in Figs. 5 and 6, by slits l whose width is ap- 55 proximately equal to the width of the bars 5 be- January 24, 1935, Serial No. 3,315 Germany January 30, 1934 tween. This fact is the r A'l'ENT OFFICE esult of the small effect of the pressure according to size and extent, in

comparison with the vacuum resistance to friction on 2 (Fig. 2) and from the edges of such slits which is greater than the resistance to the wind streaming around the body.

In order to obtain the all directions of the wind arrange a movable surface I steered by the wind instead surface i (Figs. 1 and 2) as in Figs. screening surface on the such a manner that 5 of equal width. Tests same suction effect by it is not necessary to (Figs. 3 and 4) of a fixed screening It is only necessary,

5 and 6, to arrange the slits in the whole circumference in the slits i alternate with bars have proved that then the same suction effect is produced for all horizontal directions of wind.

Having now particularly described and ascertained the nature of my what manner the same is that what I claim is:

said invention, and in to be formed, I declare 1. A head piece for an exhaust duct comprising vertically spaced strips connected together at the top and bottom, a cover connected to the strips at the top, said strips being radially equally spaced from and circumferentially spaced about a central vertical axis for at least 300 a suction area,

to function as and imperforate means radially spaced from said vertical axis, extending vertically the length of said st and circumferentially pressure area.

2. A head piece rips from top to bottom for 60 to function as a for an exhaust duct comprising a casing having a cover at the top and an open bottom, said casing being circular in horizontal cross section, spaced slits in and circumferentially arranged around said casing for at least 300 to act as a suction means extending vertically area, and imperforate from the top to the bottom and circumferentially of said casing for 60 to act as a pressure area.

3. A head piece as defined in claim 2 in which the width of each of the substantially slits within the 300 is of the same width as the portion of the casing between two which also the surface of the pressure adjacent slits and in area of 60 may be provided with slits and bars of equal width as on the remaining circumference of 300. 4. A head piece as defined in claim 2 including means to pivotally mount said imperforate means on said cover, a wind vane pivotally mounted on said cover and means to c imperforate means so onnect said vane to said that the imperforate means may be steered by the wind. 

